Automatic return guiding device for a track device

ABSTRACT

An automatic return guiding device is provided for a track device including a first track member having a base mounted to an inner end thereof and a second track member slidably mounted in the first track member. The base includes a sliding seat having a slot. The slot has a bent section on an outer end thereof. A sliding member is mounted on the sliding seat and includes at least a front leg and a rear leg that are slidingly received in the slot. An elastic element is attached between the front leg of the sliding member and a rear end of the base. The sliding member further includes an inclined face and a recessed portion following a rear end of the inclined face, with the inclined face and the recessed portion together forming a resilient plate on a body of the sliding member.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an automatic return guiding device for a track device mounted to a drawer or the like, wherein the automatic return guiding device guides the track device to a retracted state.

[0003] 2. Description of Related Art

[0004] A drawer generally includes a track device attached thereto, and the drawer is manually pulled outward to an open position or pushed inward to a closed position. In some cases, the drawer is not closed if the force for closing the drawer is insufficient, which would cause a hindrance. Automatic return guiding devices have been proposed to solve this problem, and typical examples have been disclosed in, e.g., Taiwan Utility Model Publication Nos. 348453, 468437, 525453, and 525454. In these automatic return guiding devices, a spring-biased sliding member is used to return a sliding track to its retracted position inside a fixed track. Further, a sliding member slides along a groove to a predetermined position and pulls a spring when the sliding track is moved to its extended position. The sliding member is unlatched during an end travel of the sliding member to its retracted position, and the sliding member is returned together with the sliding track under the action of the spring. Various designs with different special arrangements and different member shapes have been proposed to meet different product needs under the same operational principle.

[0005] However, it was found that some of the members of the above-mentioned designs have a relatively short life. For example, in Taiwan Utility Model Publication No. 525454, a swaying member includes an outwardly bending projection that forms a hook-like engaging portion. The sliding track includes an abutting portion for cooperating with the engaging portion. The engaging portion includes an open hook end that is deformed during operation. However, it was found that the hook-like engaging portion broke after frequent operation for a period of time. The engaging portion is generally made of plastics and thus aggravates this problem. The life of the track device is shortened.

OBJECTS OF THE INVENTION

[0006] The object of the present invention is to provide an automatic return guiding device for guiding the track device to a retracted state. The track device has a longer life through improvement in a sliding member and associated parts of the automatic guiding device.

SUMMARY OF THE INVENTION

[0007] In accordance with a first aspect of the invention, an automatic return guiding device is provided for a track device of the type including a first track member having a base mounted to an inner end thereof, a second track member mounted in the first track member, and a slide-aiding member mounted between the first track member and the second track member, the second track member including an engaging member on an inner end thereof.

[0008] The base includes a sliding seat having a slot. The slot has a bent section on an outer end thereof. A sliding member is mounted on the sliding seat and includes at least a front leg and a rear leg that are slidingly received in the slot. An elastic element is attached between the front leg of the sliding member and a rear end of the base. The sliding member further includes an inclined face and a recessed portion following a rear end of the inclined face. A cutout is defined in the sliding member and located beside the inclined face and the recessed portion, with the inclined face and the recessed portion together forming a resilient plate on a body of the sliding member.

[0009] In accordance with a second aspect of the invention, a base is provided for an automatic return guiding device for a track device. The base includes a sliding seat having a slot, the slot having a bent section on an outer end thereof. The sliding seat includes a horizontal portion in which the slot extends. The horizontal portion has a thin wall section. The slot includes a groove (64) in a rear end thereof, with the thin wall section between the bent section and the groove acting as a resilient plate.

[0010] Other objects, advantages and novel features of this invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is an exploded perspective view of a track device in accordance with the present invention;

[0012]FIG. 2 is a top view of a base of the track device in accordance with the present invention;

[0013]FIG. 3 is an elevational view of the track device in accordance with the present invention, wherein the track device is in a retracted state;

[0014]FIG. 4 is a view similar to FIG. 3, illustrating extension of the track device;

[0015]FIG. 5 is a view similar to FIG. 4, illustrating further extension of the track device;

[0016]FIG. 6 is a view similar to FIG. 3, illustrating retraction of the track device;

[0017]FIG. 7 is a view similar to FIG. 6, illustrating an end travel of the retraction of the track device;

[0018]FIG. 8 is a view similar to FIG. 6, illustrating reengagement of the track device;

[0019]FIG. 9 is a view similar to FIG. 6, illustrating another reengagement of the track device;

[0020]FIG. 10 is a top view of a modified embodiment of the base of the track device;

[0021]FIG. 11 is a sectional view illustrating operation of the base in FIG. 10; and

[0022]FIG. 12 is a top view of another modified embodiment of the base of the track device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Preferred embodiments of the present invention are now to be described hereinafter in detail, in which the same reference numerals are used in the preferred embodiments for the same parts as those in the prior art to avoid redundant description.

[0024] Referring to FIG. 1, a track device in accordance with the present invention is a three-part track device and comprises a first track member 1, a second track member 3 mounted in the first track member 1, a slide-aiding member 2 mounted between the first track member 1 and the second track member 3, a third track member 5 mounted in the second track member 3, and a slide-aiding member 4 mounted between the second track member 3 and the third track member 5. The track device can be of other types. For example, one of the second track member 3 and the third track member 5 can be omitted to form a two-part track device.

[0025] Of more importance, a base 6 is mounted to an inner end of the first track 1. The base 6 includes a sliding seat 61 that is in the form of a thin wall (but not limited to a thin wall). The sliding seat 61 includes a slot 62 having a bent section 621 distal to the inner end of the first track device 1. The bent section 621 is approximately perpendicular to a longitudinal direction of the slot 62. A sliding member 7 is mounted to the sliding seat 61 and includes at least a front leg 71 and a rear leg 72 that are slidingly received in the slot 62 and abuts against a wall delimiting the slot 62.

[0026] An elastic element 8 has an end attached to the front leg 71 of the sliding member 7, and the other end of the elastic element 8 is attached to a rear end of the base 6, thereby imparting an elastic pulling force to the sliding member 7. As illustrated in FIG. 2, the elastic element 8 is in an oblique state relative to a front end of the front leg 71, thereby pulling the sliding member 7 and causing the front end of the sliding member 7 to pivot about the rear leg 72. Further, the sliding member 7 includes an inclined face 73 that extends toward an engaging member 52 formed on an inner end of the third track member 5. The sliding member 7 further includes a recessed portion 74 following a rear end of the inclined face 73. Further, a cutout 75 is defined in the sliding member 7 and located beside the inclined face 73 and the recessed portion 74. Thus, the inclined face 73 and the recessed portion 74 together form a resilient plate on the body of the sliding member 7. Namely, the sliding member 7 is resilient and thus not easy to break.

[0027] The third track member 5 includes a notch 51 in the inner end thereof, and the engaging member 52 extends into the notch 51 for releasably engaging with the recessed portion 74 of the sliding member 7.

[0028] As illustrated in FIG. 3, when the track device is in a retracted state, the notch 51 of the third track member 5 is in the area of the sliding seat 61 of the base 6, with the engaging member 52 being engaged in the recessed portion 74 of the sliding member 7. In this state, the elastic element 8 imparts a pulling force to the sliding member 7, thereby positioning the sliding member 7 and the third track 5.

[0029] When the second track member 3 and the third track member 5 of the track device are moved outward, as illustrated in FIGS. 4 and 5, since the engaging member 52 on the third track 5 is engaged in the recessed portion 74 of the sliding member 7, the sliding member 7 is moved, with the front leg 71 and the rear leg 72 of the sliding member 7 sliding along the slot 62 of the sliding seat 61 of the base 6, and with the elastic element 8 being stretched. When the front end of the sliding member 7 reaches the bent section 621 of the slot 62, the front leg 71 of the sliding member 7 enters the bent section 621 by an inclined pulling force imparted by the elastic element 8. Further, the sliding member 7 pivots to an oblique state such that the recessed portion 74 of the sliding member 7 is disengaged from the engaging member 52 of the third track member 5. Thus, further outward movement of the track member 5 is allowed, as the track member 5 is disengaged from the sliding member 7, with the sliding member 7 being maintained in the oblique state in the bent section 621 of the slot 62.

[0030] Referring to FIG. 6, when the third track member 5 is moved inward, the engaging member 52 of the third track member 5 is moved into the recessed portion 74 of the sliding member 7 and thus abuts against a rear wall of the recessed portion 74 during an end travel of the retraction of the track device. Next, as illustrated in FIG. 7, the front leg 72 of the sliding member 7 slides from the bent section 621 into the longitudinal section of the slot 62, as the engaging member 52 exerts an inward force to the recessed portion 74 of the sliding member 7. Meanwhile, the sliding member 7 returns from the oblique state to an original horizontal state, with the recessed portion 74 being engaged with the engaging member 52 of the third track 5. The sliding member 7 and the third track 5 as well as a drawer to which the third track 5 is attached are moved inward by the returning force of the elastic element 8.

[0031] When the third track member 5 is in its extended state, the sliding member 7 that is supposed to be retained in the bent section 621 of the slot 62 might be impinged by an external force and thus disengaged from bent section 621 and then moved to an inner end of the slot 62 opposite to the bent section 621. In this case, as illustrated in FIG. 8, the third track member 5 is moved inward until the engaging member 52 moves to the inclined face 73 of the sliding member 7. The inclined face 73 deforms when the inclined face 73 is pressed against by the engaging member 52, as the cutout 75 beside the inclined face 73 and the recessed portion 74 allows deformation. As illustrated in FIG. 9, the inclined face 73 and a front end of the recessed portion 74 deform like a resilient plate, allowing the engaging member 52 to forcibly enter the recessed portion 74. The track device is then in a state shown in FIG. 3. The inclined face 73 and the recessed portion 74 that deform like a resilient plate would not break even after repeated operations.

[0032]FIG. 10 illustrates a modified embodiment of the base 6, wherein a horizontal portion of the base 6 in which the slot 62 extends includes a resilient thin wall section 63. The front leg 71 and the rear leg 72 of the sliding member 7 abut against the thin wall section 63. The slot 62 may further include a groove 64 in the inner end thereof. Thus, the thin wall section 63 acts as a resilient plate, as illustrated in FIG. 11. When the engaging member 52 presses against the inclined face 73 of the sliding member 7 located on the sliding seat 61, since the engaging member 52 presses the inclined face 73 at a point higher than the horizontal plane of the sliding seat 61, the sliding member 7 is inclined relative to the horizontal plane of the sliding seat 61. Thus, the resilient thin wall section 63 exerts a reaction force to the sliding member 7 moving on the resilient thin wall section 63, providing an inclining action to assist in moving the engaging member 52 into the recessed portion 74 of the sliding member 7.

[0033]FIG. 12 illustrates another modified embodiment of the base, wherein the thin wall section 63 includes a channel 65 extending in a direction parallel to the slot 62. Thus, the thin wall section 63 inclines more easily when the sliding member 7 moves across the thin wall section 63.

[0034] While the principles of this invention have been disclosed in connection with specific embodiments, it should be understood by those skilled in the art that these descriptions are not intended to limit the scope of the invention, and that any modification and variation without departing the spirit of the invention is intended to be covered by the scope of this invention defined only by the appended claims. 

What is claimed is:
 1. An automatic return guiding device for a track device, the track device comprising a first track member having a base mounted to an inner end thereof, a second track member mounted in the first track member, and a slide-aiding member mounted between the first track member and the second track member, the second track member including an engaging member on an inner end thereof; the base including a sliding seat having a slot, the slot having a bent section on an outer end thereof, a sliding member being mounted on the sliding seat and including at least a front leg and a rear leg that are slidingly received in the slot, an elastic element being attached between the front leg of the sliding member and a rear end of the base, the sliding member further including an inclined face and a recessed portion following a rear end of the inclined face, a cutout being defined in the sliding member and located beside the inclined face and the recessed portion, with the inclined face and the recessed portion together forming a resilient plate on a body of the sliding member.
 2. The automatic return guiding device for a track device as claimed in claim 1, wherein the inclined face of the sliding member has an appropriate height.
 3. A base for an automatic return guiding device for a track device, the base including a sliding seat having a slot, the slot having a bent section on an outer end thereof; the sliding seat including a horizontal portion in which the slot extends, the horizontal portion having a thin wall section, the slot including a groove in a rear end thereof, with the thin wall section between the bent section and the groove acting as a resilient plate. 